Use Of Doppler Echocardiography Research Articles

Influence of Doppler Sample Volume Location on the Assessment of Changes in Mitral Inflow Velocity Profiles

Previous studies that have validated Doppler indexes of mitral inflow have used pulsed wave sample volume locations either at the level of the mitral valve anulus or at the tips of the mitral valve leaflets. Although significant differences between absolute values for peak velocities and velocity time integrals at these sample volume locations have previously been reported, no information exists that has compared changes in inflow profiles after an intervention to improve left ventricular filling. To address this question, 13 patients with severe pulmonary hypertension (mean pulmonary artery pressure, 50 +/- 13 mm Hg) caused by chronic thromboembolic disease were studied with use of Doppler echocardiography immediately before and after surgical reduction of pulmonary hypertension (pulmonary vascular resistance decreased from 916 +/- 413 to 233 +/- 89 dynes.sec.cm5). This clinical model has been shown to have abnormal mitral inflow velocity profiles that improve markedly after surgery. Doppler measures of early and late peak velocities were significantly lower both before and after surgery when sampling at the mitral anulus compared with the leaflet tips, although late filling parameters and the deceleration of early flow velocity tended to differ little. With surgery, the significant increase in peak early velocity and the ratio of early to late velocity was present regardless of the sample volume location (peak E at leaflet tips, 47.1 +/- 16.0 to 68.9 +/- 15.4 [p less than 0.001], and at anulus, 40.7 +/- 11.3 to 56.2 +/- 14.6 cm/sec [p less than 0.001]; peak E/A at leaflet tips, 0.95 +/- 0.4 to 1.55 +/- 0.9, and at anulus, 0.78 +/- 0.3 to 1.32 +/- 0.7 [both p less than 0.02]).(ABSTRACT TRUNCATED AT 250 WORDS)

Complete foetal ECG morphology recording by synchronised adaptive filtration

Present noninvasively measured indices of foetal stress are indirect and not sufficient. Foetal electrocardiography (FECG) is a potential noninvasive measurement of the foetus wellbeing which has been little utilised because of the difficulties of measuring it. The development of time-sequenced adaptive filters which are synchronised to the QRS complex by the use of Doppler echocardiography allowed the recording of relatively noise-free FECG. The paper describes the use of this technique for obtaining the complete complex of the FECG. Several sets of time-sequenced adaptive filters are combined to allow a multilead abdominal recording to produce a measurement system which rejects maternal ECG and enhances the FECG. Five subjects have been analysed, and their FECGs have been accurately reproduced with minimal changes of the filters' parameters.

Endomyocardial biopsy in cardiac transplant recipients using the femoral venous approach

Right ventricular endomyocardial biopsy is currently used to evaluate myocardial disease and to assess the degree of rejection after heart transplantation. For this indication, use of Doppler echocardiography 1 by some investigators fails to confirm the rejection. 2 The techniques for right ventricular endomyocardial biopsy have been extensively described by the group at Stanford. 3 The right subclavian venous approach is recommended and the femoral approach discouraged due to the difficulties of positioning the bioptome through the tricuspid valve. Moreover, with the femoral route the specimens are often taken in the high portion of the septum, increasing the risk for transient or permanent right bundle branch block. Investigators in a previous study comparing the femoral and jugular approach for endomyocardial biopsy have concluded that the femoral route is a safe approach; they also reported a low incidence of complications. 4,5 We describe our experience with endomyocardial biopsy in heart transplant recipients using either the right or left femoral venous approach repetitively.

Use of Doppler Echocardiography and Amyl Nitrite Inhalation to Characterize Left Ventricular Outflow Obstruction in Hypertrophic Cardiomyopathy

The presence of left ventricular outflow tract obstruction (LVOTO) of either a resting or dynamic nature may have important therapeutic and prognostic implications in patients with hypertrophic cardiomyopathy (HCM). Doppler echocardiograms combined with amyl nitrite (Amyl) inhalation were performed in 333 consecutive patients referred for suspected HCM to diagnose and categorize the nature and severity of LVOTO. Hypertrophic cardiomyopathy was present by 2-D and M-mode criteria in 145/333 (44 percent) patients. Normal limits of resting and post-Amyl continuous wave Doppler peak left ventricular outflow tract velocities were established in 15 subjects with completely normal 2-D and Doppler echocardiograms. Based on these criteria, of the 145 patients with HCM, 63 (43 percent) were classified as having resting LVOTO, peak velocity 4.2 +/- 1.3 m/s. Among 82 patients with HCM without resting LVOTO, 47 (57 percent) received Amyl. Latent LVOTO was provoked in 25/47 (53 percent), peak post-Amyl velocity 4.5 +/- 1.2 m/s. The remaining 22 (47 percent) had nonobstructive HCM, as indicated by no significant increase in post-Amyl velocity. Among a total 62 subjects receiving Amyl, none experienced serious morbidity or mortality. Doppler echocardiography, in conjunction with Amyl inhalation in selected patients, is a useful noninvasive method to diagnose and categorize patients with HCM according to the nature and severity of LVOTO.

Usefulness of Doppler Echocardiography in the Diagnosis of Congestive Heart Failure

Usefulness of Doppler Echocardiography in the Diagnosis of Congestive Heart Failure

Usefulness of Doppler echocardiography in the diagnosis of congestive heart failure

One hundred fifty-one consecutive patients with a diagnosis of congestive heart failure (CHF) referred for echocardiography were prospectively evaluated to (1) define the frequency of normal left ventricular systolic function in a referral-based population with CHF; (2) establish cardiac mechanisms responsible for symptomatology in these patients; and (3) assess the ability to clinically differentiate these subsets of patients based on routine history and physical examination. Of the 151 total patients, 51 (34%) had normal left ventricular systolic function (left ventricular ejection fraction ≥55%). Primary valvular disease was present in 4 of these 51 patients (8%), and Doppler echocardiographic evidence of abnormal left ventricular filling (diastolic dysfunction) was evident in 10 (20%). In addition, no predefined resting abnormality was noted in 34 (66%) of them. Despite this finding, 51% of all patients with normal left ventricular systolic function were being treated with digoxin therapy in the absence of atrial arrhythmia. Clinical differentiation of this group of patients from those with abnormal left ventricular systolic function was difficult and may have accounted for this apparently inappropriate treatment. Thus, evaluation of left ventricular function and of causative mechanisms of CHF before initiation of long-term treatment is mandatory.

Fetal hydrops and death from sacrococcygeal teratoma: Rationale for fetal surgery

Most sacrococcygeal teratomas diagnosed before birth can be managed by planned delivery and postnatal surgery. However, large tumors early in gestation may result in placentomegaly, hydrops, and fetal death and a preeclampsia-like syndrome in the mother. This chain of events may result from high output cardiac failure in the fetus caused by arteriovenous shunting through the tumor. We recently encountered this situation in a fetus at 21 weeks' gestation and performed fetal surgery in an attempt to reverse the process. Excision of the teratoma resulted in reversal of hydrops, diminution of descending aortic flow on Doppler echocardiography, and decrease in placental thickness. Despite these changes, uterine irritability after hysterotomy resulted in labor and delivery of a nonviable premature infant. This case demonstrates that when fetal sacrococcygeal teratoma becomes very large early in gestation, high output cardiac failure can endanger both fetus and mother. In the future, use of Doppler echocardiography may allow appropriate selection of high-risk fetuses. Intervention to prevent arteriovenous shunting through the tumor may offer these fetuses an improved chance for survival.

Book reviews

Over the last few years the use of Doppler echocardiography has dramatically increased, first with the use of pulsed then continuous wave and now colour systems. As the use of Doppler echocardiography spreads from specialized cardiac centres there is a need to reduce the mystery that these techniques generate.

The Usefulness of Doppler Echocardiography for the Evaluation of Hemodynamics in Tetralogy of Fallot: Comparison of the Patients with Pre‐ and Post‐Corrective Surgery and Control Healthy Children

AbstractTwodimensional Doppler echocardiographic examinations were performed in 61 patients (39 boys and 22 girls) with tetralogy of Fallot (TOF). The patients were examined at the Department of Pediatrics, University of Tokyo, and at the Department of Pediatrics, Ohta General Hospital, in Koriyama city, Fukushima Prefecture.One hundred and eighteen healthy children (59 boys and 59 girls) were also examined at the Waseda housing complex in Misato city, Saitama Prefecture.By short axis view of aorta, samples were collected from both the right ventricular outflow tract below the pulmonary valve and in the main pulmonary artery. On the other hand, the apex four chamber view was used to collect samples at the right and left atrial outflows.Right ventricular systolic time intervals were measured both at the main pulmonary artery (PA) and at the outflow tract below the pulmonary valve (RVO).The right ventricular systolic pre‐ejection period (PAPEP) and acceleration time (PAACT), measured at the supra‐valvular site, were shorter before surgery as compared to after surgery and normals. The ratio of right ventricular pre‐ejection period to ejection time (PAPEP/ET) and the ratio of acceleration time to ejection time (PAACT/ET) were both significantly lower before surgery compared to after surgery and controls.The mean main pulmonary artery peak velocity before surgery was 369 cm/sec and the peak pressure gradient calculated with the modified Bernoulli formula was 55 mmHg.Before surgery, peak velocity of right ventricular rapid filling (R‐wave) was low, while peak velocity of atrial contraction (A‐wave) was high. After surgery, however, R‐wave increased and A‐wave decreased in velocity. The peak velocity of left ventricular filling R‐wave was also low before surgery and increased after surgery, while peak velocity of left atrial contraction A‐wave was increased before surgery and decreased to almost normal values after surgery. The left ventricular A/R ratio before surgery was also high as a result of low R‐wave velocity. The measured time interval between aortic valve closing sound and left ventricular rapid filling wave (IIA‐R time), and the measured time interval between pulmo nary valve closing sound and ventricular filling wave (IIP‐R time) were both longer before surgery than those after surgery and controls. Consequently, the measured time intervals between rapid ventricular filling flow wave and atrial contraction wave (R‐A time) for both right and left atrial were shorter before surgery than after surgery and controls. A new method for estimation of pulmonary‐to‐systemic blood flow ratio (Qp/Qs) was successfully applied to TOF, and a good correlation was obtained between Qp/Qs determined by this method and that by the Fick method.

A practical application of Doppler echocardiography for the assessment of severity of aortic stenosis

This study evaluated a strategy that makes optimal use of Doppler echocardiography for estimating the severity of valvular aortic stenosis (AS). Fifty-eight patients with no more than moderate aortic insufficiency who underwent cardiac catheterization were evaluated with two-dimentional echocardiography and Doppler velocimetry to determine the peak velocity across the stenotic valve and aortic valve area (AVA) by means of the continuity equation. All 33 peak Doppler velocities of ≥ 4 m/sec had critical AS (AVA ≤ 0.8 cm 2 at catheterization). Conversly, six of seven patients with Doppler velocities of ≤ 3 m/sec had noncritical AS. The patient with a falsely low peak velocity had severely depressed left ventricular function. Doppler velocity alone was inadequate in determining severity of AS for patients with velocities between 3 and 4 m/sec. The continuity equation proved accurate in estimating AVA in the 46 patients for whom catheterization and ultrasound data were sufficient to compare calculated AVA ( r = 0.81), and was also accurate for those patients with peak Doppler velocities between 3 and 4 m/sec ( r = 0.90). These results suggest that Doppler velocimetry alone is adequate in determining critical vs noncritical AS in many patients, while the continuity equation should be applied for patients with peak velocities between 3 and 4 m/sec as well as in patients with severely depressed cardiac function.

Usefulness of doppler echocardiography in the management of patients with mitral stenosis during pregnancy

Usefulness of doppler echocardiography in the management of patients with mitral stenosis during pregnancy

Clinical utility of Doppler ultrasound in cardiac diseases.

During the past decade Doppler echocardiography has evolved to an extent that it has become a major noninvasive tool for cardiac evaluation in both acquired and congenital heart disease. This article describes current applications of Doppler techniques in the evaluation of cardiac anatomy and hemodynamics. The principles and methods employed in the use of Doppler echocardiography are described and illustrated for assessment and quantitation of flow velocities, pressure gradients, valve areas, valve regurgitation, stroke volume, cardiac output, cardiac shunts, and diastolic filling indices. The increasing accuracy of these applications has led to a substantial reduction in the need for invasive diagnostic methods, such as cardiac catheterization, especially in patients where frequent follow-up evaluations are indicated.

Left Ventricular Ejection Dynamics in Hypertrophic Cardiomyopathy and Aortic Stenosis: Comparison with the Use of Doppler Echocardiography

Left Ventricular Ejection Dynamics in Hypertrophic Cardiomyopathy and Aortic Stenosis: Comparison with the Use of Doppler Echocardiography

Transseptal Doppler flow velocity profile in acquired ventricular septal defect in acute myocardial infarction

Ventricular septal defect (VSD) is a potentially fatal complication of acute myocardial infarction (AMI), occurring in approximately 1% of cases. 1 Although physical examination may suggest VSD, unequivocal differentiation from mitral regurgitation is not possible clinically and the definitive diagnosis is conventionally established by demonstrating a step-up in oxygen saturation in the right side of the heart. AMI-induced VSD can be visualized by careful inspection of the ventricular septum with 2-dimensional (2-D) echocardiography in most patients, and is more often detected with inferoposterior than with anteroseptal AMI. 2,3 Doppler echocardiography allows documentation and localization of abnormal flow across the ventricular septum even when the VSD cannot be visualized. Although use of Doppler echocardiography in the diagnosis of AMI-induced VSD has been reported, the blood flow velocity spectra across the VSD have not been fully characterized throughout the cardiac cycle. 2–5 This study was performed to characterize the pattern and timing of shunt flow across AMI-induced VSD throughout the cardiac cycle.

The Use of Doppler Echocardiography for Detection and Estimation of Severity of Patent Ductus Arteriosus, Ventricular Septal Defect, and Atrial Septal Defect

The Use of Doppler Echocardiography for Detection and Estimation of Severity of Patent Ductus Arteriosus, Ventricular Septal Defect, and Atrial Septal Defect

Determination of central hemodynamic parameters by Doppler echocardiography

Doppler echocardiography (ultrasound pulse-Doppler location) is used in medical practice in our country and abroad mainly for diagnostics of various heart defects. Using this method it is possible to non-invasively study blood flow in the heart chambers, the mouth of the main vessels, to detect changes in hemodynamics and accurately diagnose heart defects, including combined ones. The use of Doppler echocardiography in clinical practice has shown that its informative value increases with quantitative assessment of Doppler frequencies, comparing changes in their spectrum over time.

Left ventricular ejection dynamics in hypertrophic cardiomyopathy and aortic stenosis: Comparison with the use of Doppler echocardiography

Left ventricular ejection dynamics of 15 patients with hypertrophic cardiomyopathy (nine obstructive, six nonobstructive) were compared to those in 12 age-matched normal subjects and 10 patients with valvular aortic stenosis by means of combined two-dimensional and Doppler echocardiography. Doppler peak flow velocities in obstructive (HOCM, 2.5 ± 1.3 m/sec) and nonobstructive (HNCM, 2.6 ± 0.6 m/sec) hypertrophic cardiomyopathy, as well as in patients with aortic stenosis (AS, 3.6 ± 1.3 m/sec) were significantly higher than in the normal population (1.0 ± 0.2 m/sec; p < 0.001 for all comparisons), but did not differ from each other. The HOCM patients had time to peak velocity (154 ± 55.7 msec) that was higher than that in both HNCM (86 ± 8.4 msec) and normal groups (84.5 ± 8.9 msec; p < 0.001 for both comparisons), but did not differ from those in AS (117 ± 52.5 msec). the total ejection time did not differ between HOCM (348.2 ± 91.1 msec) and AS (323.8 ± 30.4 msec) groups, but was prolonged in HOCM compared to HNCM (198 ± 21.0 msec) and normal groups (233 ± 28.3 msec; p < 0.001 for both comparisons). The normal and HNCM groups did not differ in time to peak or total ejection time measurements. The percent of flow velocity present in the initial third of the systolic velocity integral for HOCM (44.5% ± 5.9) and HNCM (49.4% ± 2.5) groups was greater than for normals (36.2% ± 5.4; p < 0.05 for both comparisons), but HOCM values did not differ from HNCM values. We conclude that the ejection dynamics in HOCM differ from those in HNCM. HOCM shown left ventricular ejection dynamics similar to that of valvular aortic stenosis, suggesting an outflow impedance in HOCM, while HNCM exhibits ejection dynamics similar to that of the subjects with normal left ventricular outflow.

Pulsed Doppler echocardiographic assessment, including use of aortic leaflet separation, of cardiac output in children with structural heart disease

Use of Doppler echocardiography for determining cardiac output has been widely investigated and validated. 1–6 Validation of this technique in children with congenital heart disease is limited, 3,4,7 and some problems, such as obtaining adequate Doppler samples and choice of sample sites, are of concern. This study was undertaken to validate the technique against indocyanine green dye curves in children with structural heart disease during cardiac catheterization or after surgical repair with particular reference to the optimal site for assessing aortic cross-sectional area for the calculation of cardiac output.

Hemodynamic consequences of left atrial myxomas as assessed by Doppler ultrasound

Seven patients with left atrial (LA) myxoma who were studied by M-mode, two-dimensional, and Doppler echocardiography and who underwent surgical excision of the tumor are described. In six patients, the myxoma was attached to the lower interatrial septum and was protruding through the mitral valve (MV) during diastole. Significant MV obstruction (mean diastolic gradient of 16 mm Hg) was detected by Doppler in only one patient and was confirmed by hemodynamic studies; another patient had only a small gradient (peak 8 and mean 4 mm Hg). Mild mitral regurgitation (MR) was found preoperatively in four of five patients who underwent left ventriculography, but was not detected by Doppler. Postoperatively, however, five patients were found to have mild MR and one patient had moderate MR by Doppler. The use of Doppler echocardiography can provide important additional information regarding the hemodynamic consequences of LA myxomas.

Determination of the mean pressure gradient in aortic stenosis by Doppler echocardiography

Measurement of the mean pressure gradient across the stenotic aortic valve provides important information about the severity of aortic stenosis. However, determination of the mean pressure gradient by Doppler echocardiography has been difficult due to the squared relation between instantaneous velocities pressure gradients. In this study, the velocity curves in aortic stenosis were analysed mathematically to develop a new and simple method for calculating the mean pressure gradient (delta Pm) from Doppler velocity tracings. The new formula is: delta Pm = 8 V2m[Vp/(Vp + Vm)] where Vp is the peak systolic velocity and Vm the mean systolic velocity. Doppler echocardiography and cardiac catheterisation were performed in 41 patients with aortic stenosis to evaluate the accuracy of this mathematical method. There was a high correlation between the peak pressure gradients determined by Doppler technique using a modified Bernoulli equation and by catheterisation (r = 0.95, SEE = 8.58 mmHg), and the difference between the two measurements was not significant. The comparison between the mean pressure gradients determined by Doppler echocardiography using the new formula and by catheterisation yielded a high correlation (r = 0.95, SEE = 5.60 mmHg), and there was no significant difference between the two means. These results demonstrate the reliability of Doppler echocardiography for determining the mean pressure gradient in aortic stenosis using our mathematical method. Measurement of the mean pressure gradient will further enhance the usefulness of Doppler echocardiography in the non-invasive evaluation of patients with aortic stenosis.